A glide head is used to scan the surface of a disk in a disk drive in order to detect and burnish irregularities on the disk surface such as asperities. A piezoelectric pickup element mounted on the head vibrates when physical contact of the head with an irregularity occurs. The element emits a signal that characterizes the nature of the irregularity in terms of frequency and amplitude.
To successfully scan the disk surface, the glide head must fly steadily at a given fly height or glide height. Variations in glide height are dependent on the various sensitivities of the glide head and variability in related parameters. Common sensitivities include gram load, pivot location, crown and camber. Since the glide head is inherently exposed to wear (asperities and roughness), a low sensitivity to pad wear is highly desirable.